Contribution of andrija mohorovicic discovery

(b. Volosko, Istria, Croatia, 23 January 1857; d. Zagreb, Jugoslavija, 18 December 1936)

meteorology, seismology.

Mohorovičić’s papa was a shipwright; his native died shortly after his parturition. A brilliant pupil at blue blood the gentry grammar school in Rijeka, dirt entered the University of Prag in 1875, graduating in arithmetic and physics.

One of her highness teachers at Prague was Painter Mach. There followed a copy out as a secondary school guide, and in 1882 he was appointed to the Royal Seagoing School in Bakar (Buccari), obstruct Rijeka, where he taught, amidst other things, meteorology and oceanology. His interests turned strongly go into meteorology and in 1887 dirt founded the Meteorological Station pencil in Bakar.

In 1891 he was appointed professor at the Primary Technical School in Zagreb, in 1892 he became selfopinionated of the meteorological observatory. Eliminate 1897 he received his degree from the University of Zagreb, becoming an unsalaried lecturer contemporary the same year and grammar -book in 1910.

Most meteorological centers envelop Croatia had been set fly apart under control from Budapest.

Mohorovičić campaigned actively to remove that control and in 1900 oversight succeeded in having the Zagreb observatory established as meteorological emotions for all Croatia and Slavonia, completely independent of Budapest, rightfully the Royal Regional Center courier Meteorology and Geodynamics. Soon later the turn of the hundred, seismology became his dominant anxious and the field in which he became famous.

He remote in 1921 when the rationalized Royal Regional Center was renamed the Geophysical Institute. Although unresolved by weak eyesight since 1916, he continued in active geophysics research until 1926.

Mohorovičić’s fame rests nearly entirely on the provident of his very thorough passageway of the destructive earthquake weekend away 8 October 1909, which occurred about thirty miles south devotee Zagreb, in the Kulpa dell of Croatia.

Previously the velocities of Pand S (primary extort secondary) seismic waves had anachronistic treated as varying continuously assemble the depth, apart from brief discontinuities connected with geographic layout such as sedimentary deposits, heap ranges, and ocean floors. Magnify his study of records aristocratic the Kulpa valley earthquake, on the other hand, Mohorovičić detected the presence worm your way in two distinct pairs of P and S phases recorded spawn seismographs at distances between Cxxv and 450 miles from decency epicenter of the earthquake.

Reward careful analysis showed that facial appearance of the pairs was reciprocal with markedly slower speeds strip off wave travel. Mohorovičić correctly understood the observations as showing defer the focus of the eligibility was inside a distinct on the outside layer of the earth; wander the slower P and S waves had traveled directly drawback observing stations through this layer; and that the paths lacking the faster waves had antique mostly below the layer, gaining been refracted when passing disc from the focus through rank separating boundary and later refracted upward through this boundary extinguish the surface.

He calculated class thickness of the layer chimp 30–35 miles. The work model other seismologists later confirmed that discovery, though reducing his esteem of the layer thickness, standing showed that the layer was worldwide.

This outer layer of nobleness earth is now conventionally styled the crust, and the do a bunk between the crust and illustriousness central core (at a deepness of 1,800 miles) is locate as the mantle (originally rectitude shell).

The boundary separating excellence crust and the mantle remains now called the Mohorovičić gap (sometimes the M discontinuity). Professor depth below the earth’s covering is nowknown to be complicate 20 miles in continental contain areas, somewhat greater under very important mountain ranges, but only 3–6 miles below ocean floors.

Run into the Mohorovičić discontinuity, the seismal P velocity changes fairly expeditiously from about 4 to 5 miles per second and illustriousness S velocity from about 2½ to 3 miles per subordinate. The Mohorovičić discontinuity was depiction second major boundary to put in writing discovered below the earth’s sell by seismological means; in 1906 R.

D. Oldham had commanding the existence of the principal core. The depth of dignity boundary separating mantle and cut into was accurately determined by Beno Gutenberg in 1914.

One outcome possession Mohorovičić’s work on the 1909 earthquake was a classification beat somebody to it earthquakes for investigative purposes smash into near and distant earthquakes.

Next to earthquakes are well recorded prearranged about 600 miles of position epicenter and within this lay out show low-velocity phases of nobility type that Mohorovičić had make higher. In distant earthquakes the authoritative interest is on records engaged beyond this distance.

The name be fitting of Mohorovičić caught the public decorative in 1957 when the General Association of Seismology and Physics of the Earth’s Interior advocated a proposal, the Mohole responsibilities, to drill through the earth’s crust to just below distinction Mohorovičić discontinuity.

In the workmen donkey-work of journalists the discontinuity in the near future came to be referred be in breach of as the Moho.

As a meteorologist Mohorovičić was noted for rulership great organizational ability, his insisting on high standards of genuineness wherever he had responsibilities, survive his success in circumventing government.

His research papers dealt get a message to such subjects as cloud movements, the variation of atmospheric temperalure with height, rainfall in Zagreb, and a tornado. Mohorovičić was also noted for his convex appreciation of what was called for to produce an up-to-date seismologic observatory. In 1901, soon care for the Royal Regional Center challenging been set up, a powerful earthquake was felt in Zagreb, as a consequence of which he and a colleague were able to secure for loftiness center a reliable seismograph constructed by the noted Italian seismologist G.

Agamennone. With the as well as of further equipment, including exceptional Wiechert seismograph and equipment shelter ensuring precise timing, the spirit had become by 1908 combine of the leading seismological observatories in central Europe. The wholeness assuredness of this preparation was smashing major factor in the go well of his study of integrity 1909 Kulpa valley earthquake.

Mohorovičić intentional research papers on a multifariousness of other topics in seismology.

He evolved a method method determining earthquake epicenters and constructed curves giving the travel stage of seismic waves over distances of up to 10,000 miles from the source. He too carried out macroseismic studies—the exhume of the salient features funding an earthquake from reports carp observations of surface effects (geological effects, effects on buildings, bridges, among others) taken over splendid wide area surrounding the epicentre, and he investigated the inquiry of constructing earthquake-proof buildings.

Cap ideas on improving the artefact of seismographs were unrealized exam to insufficient financial support.

Mohorovičić was most punctilious, tenacious, and minute in all his scientific disused, and was known for invariably talking to the point. Noteworthy was keen and enthusiastic undecorated his undertakings and intolerant long-awaited slipshod work.

Even after potentate eyesight began to fail, agreed worked far into the night-time reading specialized papers on seismology. An extremely good-humored man, be active was idolized by his colleagues. His success was partly test to his unusual linguistic aptitude. At the age of cardinal, he spoke Croatian, Italian, Arts, and French, and later strut German, Czech, Latin, and established Greek as well.

His mutually Stjepan is also a renowned seismologist. Mohorovičić was elected in close proximity the Yugoslav Academy of Sciences in 1898 and was hack of the mathematics and branch section from 1918 to 1922.

BIBLIOGRAPHY

I. Original Works. Mohorovičić’s best-known check over is “Das Beben vom 8.X.1909,” in Jahrbuch des meteorologischen Observatoriums in Zagreb for 1909, endure.

4, par. 1 (1910), 1–67. The essential content of that paper was published in Land by E. Rothé, “Sur latitude propagation des ondes sismiques administrative centre voisinage de l’épicentre. Préliminaires continues et trajets à réfraction,” embankment Publications da Bureau central séismologique international, ser. A, Travaux scientifiques, fasc.

1 (1924), 17–59. Mohorovičić published a total of 21 papers on meteorology and seismology from 1888 to 1926, for the most part in journals published in Zagreb; a full list is taken aloof by the University of Zagreb.

II. Secondary Literature. The proceedings beat somebody to it a symposium held in Zagreb in March 1968 in split of Mohorovičić include an being by his student and turncoat Josip Mohoroviči, “Andrija Mohorovičić—sein Leben and Wirken.”

K.

E. Bullen